Catherine Parker More than its star attraction (Old Faithful), the Upper Geyser Basin boasts not only the largest concentration of geysers in the park, but also in the entire world (Yellowstone is ...

Lightning strikes above the Fan and Mortar geysers in Yellowstone's Upper Geyser Basin. Geysers are formed when underground water meets superheated rock and blasts back out through a narrow hole.

If you want to view Yellowstone's geysers sans crowds ... to bike to the trail rather than hike. The Lone Geyser Trail is in Upper Geyser Basin, about 3.5 miles south of the Old Faithful overpass ...

Yellowstone National Park holds some of ... a natural hot spring that tops the highlights in this area called Upper Geyser ...

A Seattle tourist will serve one week in prison for walking off the boardwalk at Yellowstone National ... located in the Upper Geyser Basin, erupts more frequently than any other large geyser ...